Chair car and Passenger car

Chair car noun - A passenger car for day travel; you pay extra fare for individual chairs.

Passenger car and chair car are semantically related. In some cases you can use "Passenger car" instead a noun phrase "Chair car".

Passenger car noun - A railcar where passengers ride.

Chair car and passenger car are semantically related. Sometimes you can replace phrase "Chair car" with "Passenger car", this phrases are similar.